You can click on the settings of the mobile phone, select the middle system settings option, and move to the bottom about the mobile phone. You will see the model: MI-ONE plusAndroid version: 2.3.5 (this is the Android version) and then move to the lowest version number: MIUI-2.3.5 with a letter, which is the specific version of your mobile phone system. This is an Android system with MIUI. The ever-changing lock screen and shortcut switch of notification bar, such as guest mode, are not available in other mobile phone systems. I hope I can help you, adopt.